Do you actually know what a hone is used for? They’re used to remove glazing and resurfacing the inside of a cylinder which helps lubricate the piston rings and the cylinder. This is done by scoring the sidewalls.
the correct tool for this would be is a Reamer, used to open up a hole to a greater tolerance and make sure its nice and smooth.
you won’t see a hone in a bike shop. Use the right tool for the Job!
Everyone seems to jump the gun. Giving advice to someone, that could ruin his bike. a bit of emery paper and wet and dry would be my first option. It’s more than likely it only needs a quick rub on the top edge and the slot.